The invention relates to a gather-stitcher machine for joining and binding, or rather stapling, a plurality of stacked sheets of a printed or other publication, especially a magazine, comprising a transport mechanism and feeder guide mechanisms for placement of the stacked sheets onto the transport mechanism. The invention is also directed at a method for producing a thumb-tab index on printed or other volumes that are to be bound, or rather stapled, by means of a gather-stitcher machine, and in particular for producing a thumb-tab index on magazines.
It is known to provide printed volumes such as, for example, pocket calendars, lexicons, address books or the like with a thumb-tab index, which is normally arranged along the open long side of the bound volume and makes it possible to quickly open the calendar, lexicon, or the like, at an exact page. For this purpose the user of the publication can place a finger in a punched-out index tab portion along the long edge of the individual pages; upon then flipping open the volume all the pages lying to the rear of the finger are held back by the latter, while the remaining sheets which are provided with the punched-out portion are able to flip past the finger. This means that an alphabetically arranged lexicon or address book can easily be opened at the first page of any given letter of the alphabet; calendars can quickly be flipped open at the correct place, according to days of the week or to months.
In the past it has only been possible to produce such thumb-tab indexes at great expense and in a very labour-intensive manner, especially in the case of stitched volumes, as the punched-out portions cannot be produced in the individual stacked sheets, which have been joined together and stapled by a gather-stitcher, until said stacked sheets have been deposited on the transport mechanism of the gather-stitcher machine. The reason for this is that the individual stacks of sheets, which usually contain between four and one hundred pages of what will form the printed volume, but which may also consist of a single signature (section), have to be opened by feeder guide mechanisms parallel to their central stitching crease in order that they can reliably be deposited onto the gathering line or the inverted V-guide of the transport mechanism. To this end, however, it is necessary for grippers incorporated on the feeder guide devices to be able to grasp the stacks of sheets along the entire length of their long edges, something which cannot be guaranteed in cases where index tab portions have already been punched out.
Therefore it has not so far been possible to use a machine to provide punched-out portions for a thumb-tab index on printed or other volumes held together by means of staples along the crease forming the stapled spine, and instead the volumes, once they have been stapled together, have to be opened at the correct place by hand and deposited onto a punching mechanism by means of which the punched-out portions can then be produced. Using this procedure even an experienced worker is scarcely able to produce more than one hundred copies of an edition that is to be equipped with merely a weekly index.
As a consequence of the above-outlined, previously usual method of producing a thumb-tab index on stapled printed or other publications, the latter are disproportionately expensive to manufacture and are limited to small production runs. Up till now it has not been economically viable to give publications involving large production runs and a comparatively low selling price, for instance in particular TV programme guides or the like, a thumb-tab index incorporating punched-out portions arranged one above the other in a relatively narrow zone along the open long edge of the stapled magazine or the like, in order to make it possible to open the magazine at the particular desired weekday. In order, nevertheless, to enable even these publications which are produced in large quantities and very quickly at a low price to be flipped open quickly, the proposal has been made to vary from day to day the width of the pages for the individual days of the week of a television guide and to staple the pages of varying widths one in front of the other in such a way that the first day of the week appearing in the programme guide has the smallest page width and the last day the greatest page width. However, in the case of such an arrangement, particularly where a large number of individual indexes is concerned, as for example in the case of a magazine guide that covers a period of a fortnight, a great deal of space is taken up on the pages of the first days of the index.
It is the object of this invention to create a gather-stitcher machine permitting automated production of a thumb-tab index on printed or other publications intended to be held together by stapling them, in particular magazines. The invention is also aimed at providing a method for automated production of a thumb-tab index on printed or other publications that are to be assembled using a gather-stitcher machine.
Using a gather-stitcher machine of the type mentioned in the introduction, this object is achieved by the fact that it incorporates at least one edge punching device arranged behind a feeder guide device in the transport mechanism""s direction of travel. Under the method according to the invention, in the case of such a gather-stitcher machine first of all a sheet stack consisting of at least a single signature (section) is placed onto a transfer and/or processing mechanism of the gather-stitcher and then at not less than one long edge of the sheet stack first punched-out portions are made by means of the edge punching device arranged to the rear of the sheet stack placement point in the direction in which the transport mechanism advances. Next a further sheet stack is deposited onto the sheet stack previously equipped with punched-out portions and resting on the transport mechanism, thereby producing further punched-out portions which involve only the signatures of the additional sheet stack, these punched-out portions being offset in the longitudinal direction of the stack with respect to the punched-out portions in the stack of sheets underneath. This step of the process is then repeated until the desired number of index tabs has been made in the magazine or the like, after which the publication can then be finished by depositing further unpunched sheet stacks and/or stapling together the stacks which lie one above the other.
Therefore under the invention the per se known gather-stitcher machine, as has already long been standard practice in the manufacture of stapled magazines produced in large runs, has been extended to incorporate a function whereby in addition to the hitherto familiar machine units it is equipped with at least one edge punching device by which the individual punched-out portions are made on the stacks of sheets which are deposited in turn one on top of the other onto the transport mechanism.
The transport mechanism preferably consists essentially of a transfer and gathering line and/or an inverted V-shaped gatherer with driving dogs for the stacks of sheets. A particularly practical form of embodiment of the gather-stitching machine according to the invention results if an edge punching device is allocated to each of a plurality of feeder guide mechanisms. In this arrangement the individual sheet stacks to be given punched-out portions are therefore processed by different edge punching devices, with the result that the punching tools do not need to be set up each time for every new sheet stack, since each punching device always produces punched-out portions at exactly the same location.
The edge punching device preferably has punching tools and a stack guiding unit arranged ahead of the punches in the direction of travel. The stack guiding unit sees to it that the sheet stacks are guided accurately to the punches, with the result that their long edges always pass exactly into the correct position beneath and between the punches, which means that the punched-out portions are also always produced at the same, desired location. The stack guiding unit may consist essentially of at least one sheet marshalling arrangement which leads the edge regions of the sheet stack to the punches, said arrangement opening the sheet stacks suspended by their stapling crease over the inverted V of the gatherer or the gathering line of the transport mechanism and lifting them in the vicinity of the outer long edges, with the result that the leaves of the sheet stack are punched not whilst suspended, but in a substantially horizontal position. So that during the punching operation the sheet stacks are not raised from the transport mechanism or the stack guiding unit and the individual leaves of any sheet stack cannot also become displaced against one another, there is preferably allocated to the stack guiding unit a sheet retaining device which holds the individual sheets of a sheet stack safely on one another. One sheet retention device with particularly low susceptibility to malfunctioning may for example consist essentially of a pressure roller arrangement acting on the sheet stack and/or of an upper and lower belt guide, between which runs the sheet stack that is to be punched.
The punching tools of the edge punching device are preferably arranged on at least one punching table which is aligned parallel to the direction in which the sheet stack travels and which supports the sheet stack in the area of one of its long edges; in the area of their long external edges the punching table forms a firm support for the pages of the stack of sheets being processed, thereby ensuring that all the sheets of the stack are punched through cleanly. It is especially advantageous if to either side of the transport mechanism the edge punching device features a respective punching table, with associated punches, to support the sheet stacks in the area of their long edges, for then the sheets of the sheet stack can simultaneously be punched on both outer edges with punched-out portions which for producing the thumb-tab index are not normally situated at the same point of the long edges, but offset with respect to one another.
Ideally the punching tools are arranged so as to be adjustable in the direction of travel and/or transversely to the direction of travel of the stacks of sheets. This makes it possible to alter the position of the intended punched-out portion longitudinally and/or transversely to the longitudinal direction of a sheet stack as it travels through and thus to produce different indexes in printed or other publications. Naturally the blades of the punching tool may also be designed to be interchangeable, thereby enabling punched-out portions with different cross-sections to be produced, for example punched-out portions with a semi-circular cross-section, rectangular cross-section, etc.
It is especially advantageous if the punching tools consist essentially of at least one punching roller adapted to be driven in rotation, thereby producing very clean punched sections in the sheet stacks as they pass through. Preferably the punches have a drive adapted to be synchronised at the rate of travel of the transport mechanism, with the result that fluctuations in the rate of travel of the transport mechanism have no effect on the position of the punched-out portions produced using a punching device.
It is particularly advantageous if the gather-stitcher machine features a shroud which is arranged behind the edge punching device in the direction of travel and which at least partially covers the transport mechanism and the sheet stacks being conveyed by it. After the punched-out portions have been made in a first sheet stack, the latter is then moved on by the transport mechanism and arrives beneath the shroud, with the result that a subsequently deposited, additional sheet stack is deposited not straight onto the first stack, but onto the shroud above it. This makes it particularly easy to make the next punched-out portions merely in the signatures of the second sheet stack, since there is no possibility of the individual sheets of the first sheet stack beneath the shroud also being able to get into the punches for the second sheet stack. It is particularly advantageous if the shroud for a first sheet stack merges into a sheet marshalling arrangement for a following sheet stack, thereby resulting in a particularly simple engineering design configuration.
It is preferred if the gather-stitcher machine incorporates an underpressure device which is assigned to the stack guiding unit, the punching table and/or the sheet marshalling arrangement and which sees to it that the sheets of the individual stacks of sheets cannot lift away from these components, but are sucked against them on account of the vacum which prevails.